Rollerskates, Sore Butts and a Very Good Time

Grana (Cheri-Josh's Mom) got the kids rollerskates for Christmas. The backyard had been a mess so the kids weren't able to use them yet. Josh finally cleaned up the backyard and the rollerskates got strapped on. It was great. Kaytlin fell a lot at first but then she got the hang of it real quick, Isaac....not so much. He knew he was going to fall so he would purposely fall. He spent more time on the ground than anything. Once they were comfortable enough in the backyard we headed to the street. Yeah Kaytlin bailed on her butt a bit. Isaac kept falling. Josh had to join the fun and put his blades on. He took the kids a bit. On one of his solo acts he biffed, and I mean hard. The kids had tons of fun, that's all the matters, right. Except that Kaytlin's pore bum was sore for a week. She never anticipated the falls like Isaac. She would go all out and biffed, like somoeone else I know. Who could that be?